The cash gift has been made anonymously – and has instantly more than trebled the amount raised since the fund was launch in late October.

Members of the Lowther Trust, which manages the Lytham attraction, are keen to generate as much public backing as possible as they aim to gather the £1,5m needed for the first phase of a £5.25m three-phase project intended to regenerate the venue in time for its centenary in 2021.

A band of names on the glass atrium which will be a key feature of the first phase and sponsored seats are among the items which have attracted an encouraging early wave of early donations.

With work set to start next summer on the key initial stages of the project, the project has recently received the boost of being chosen as a beneficiary of next year’s St George’s Day Charity Festival.

But Trust chairman Tim Lince and colleagues were stunned when they were contacted by a local businessman and his wife who said they wanted to pledge the six-figure sum to the fund-raising drive.

“They are determined to remain anonymous but have said they want to do everything they can to make sure a legacy is left by the present generation for future residents to enjoy,” said Tim.

“They recognise that it was only through the foresight of the wealthy benefactor Squire J Talbot Clifton, who bequeathed the Lowther Gardens to the people of Lytham in 1872, that the town has such a fantastic facility. The Pavilion was built on the land in 1921.

“We have been completely bowled over by the donation. The money will be key towards our aim of a state-of-the-art building with comfortable facilities which reflects the beautiful surroundings in which it is situated.

“This has truly been a most magnificent Christmas present for all the community.”

Coun Cheryl Little, chairman of Fylde Council’s tourism and leisure committee and a Lowther trustee, said: “Lytham St Annes is a wonderful place to live and this is made all the better by the generosity shown by individuals who live and work here to enable us to develop this community facility for everyone.”